I have a 2 in 1 rear carrier (the combined low level backrest and rear carrier thing) and I'm looking to find a way to attach a spare wheel vertically without having to buy a completely new 3 or 4 in 1 carrier. Does anyone know of a bracket or attachment that will fit a spare wheel vertically to a standard rear carrier? I would've thought it's quite a cheap and simple piece of kit but, hell, what do I know?